The present invention is directed to bicycles and, more particularly, to various features of an electronically controlled bicycle transmission.
Automatic transmission devices have been installed on bicycles to conduct appropriate shifting according to the running condition of the bicycle. Such transmissions reduce the burden on the rider to manually operate the transmission and provide for easy and pleasant travel. Automatic transmissions may comprise a motor for driving the transmission, a sensor for detecting a running condition of the bicycle such as bicycle speed, and a control unit for operating the motor based on the detection results.
Some known automatic transmissions include a sound-producing device such as a buzzer or the like, and the sound-producing device produces a sound when a signal for operating the motor is transmitted. As a result, the rider is informed of the shifting operation only at the instant when the actual shifting operation is conducted. Even if the warning sound is generated slightly before the shifting operation, there is little benefit to the rider because the shift operation is conducted immediately thereafter. Usually, the rider wants to know a present riding status relative to a shift operation or whether or not a shift operation is about to be conducted during travel in an automatic operating mode. This is because the rider sometimes has a feeling of discomfort if rapid shifting is conducted unexpectedly.
The present invention is directed to features of a method and apparatus for informing a rider of an upcoming shifting operation in a bicycle transmission. In one inventive feature, the apparatus comprises a running condition detecting mechanism that detects a running condition of the bicycle, a control mechanism that provides a signal that commands the shifting operation when the running condition reaches a threshold value, and a warning mechanism that warns the rider when the running condition approaches the threshold value. An inventive method comprises the steps of detecting a running condition of the bicycle, providing a signal that commands the shifting operation when the running condition reaches a threshold value, and warning the rider when the running condition approaches the threshold value. Additional inventive features will become apparent from the description below, and such features may be combined with the above features to provide additional inventions.